The LM129 and LM329 family are precision multi-current temperature-compensated 6.9V zener references with dynamic impedances a factor to 100 less than discrete diodes. Constructed in a single silicon chip, the LM129 uses active circuitry to buffer the internal zener allowing the device to operate over 15 mA range with virtually no change in performance. The LM129 and LM329 are available with selected temperature coefficients 0.002, 0.005 and 0.01%/�C. These references also have excellent long term stability and low noise. A new subsurface breakdown zener used in the LM129 gives lower noise and better long-term stability than conventional IC zeners. Further the zener and temperature compensating transistor are made by a planar process so they are immune to problems that plague ordinary zeners. For example, there is virtually no voltage shift in zener voltage due to temperature cycling and the device is insensitive to stress on the leads. The LM129 can be used in place of conventional zeners with improved performance. The low dynamic impedance simplifies biasing and the wide operating current allows the replacement of many zener types. The LM129 is packaged 2-lead TO-46 package and is rated for operation over to +125�C temperature range. The LM329 for operation over 70�C is available in both a hermetic TO-46 package and a TO-92 epoxy package.Features
15 mA operating current 0.6 dynamic impedance at any current Available with temperature coefficients 0.001%/�C 7�V wideband noise 5% initial tolerance 0.002% long term stability Low cost Subsurface zenerTypical Applications
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. (Note 3) Reverse Breakdown Current Forward Current 2 mA
Operating Temperature Range LM129 LM329 Storage Temperature Range Soldering Information TO-92 package: 10 sec. TO-46 package: 10 sec.
B, C Parameter Reverse Breakdown Voltage Reverse Breakdown Change with Current (Note 4) Reverse Dynamic Impedance (Note 4) RMS Noise Long Term Stability (1000 hours) Temperature Coefficient LM329C LM329D Change In Reverse Breakdown Temperature Coefficient Reverse Breakdown Change with Current Reverse Dynamic Impedance 0.8 1
Note 1: "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. Note 2: These specifications apply for TA +125�C for the LM129 and TA +70�C for the LM329 unless otherwise specified. The maximum junction temperature for is 150�C and is 100�C. For operating at elevated temperature, devices in TO-46 package must be derated based on a thermal resistance of 440�C/W junction to ambient or 80�C/W junction to case. For the TO-92 package, the derating is based on 180�C/W junction to ambient with 0.4" leads from a PC board and 160�C/W junction to ambient with 0.125" lead length a PC board. Note 3: Refer to RETS129H for LM129 family military specifications. Note 4: These changes are tested on a pulsed basis with a low duty-cycle. For changes versus temperature, compute in terms of tempco.